[Theleman]

Great points !! Thanks

This Kay was cheap but interesting guitar as you say, and looks cool.
I was shocked to notice no truss rod for a steel string guitar, but then all 1960s guitars have no truss rod?

The neck is definitely bowed, measuring pressing at 12th fret the gap is about 1 - 1.5mm between the string and frets. My other guitars have no gap or gap of thin paper.

Playable with tuned down about 1.5 - 1 step. Sounds very loud and full.
When tuned to standard tuning, it sounded boxy, nasal and echoing.

I think I will just play it like that - heat treatment on the neck is way above my limit of tools, knowledge and experience right now.